(a) Field of the Invention
This invention generally relates to a safety hook, and more particularly to a hook for use with a safety lanyard. The hook including a gate for covering the mouth of the hook and a locking mechanism for controlling the opening of the gate.
(b) Discussion of Known Art
Safety hooks or snap hook, meaning hooks that include some sort of gate that closes the mouth of the hook in order to prevent the release of the hook have been used for various purposes. An important use of these snap hooks is in the area of worker safety, or fall protection. In this field, snap hooks are typically used for tethering an individual by way of a lanyard to a support structure.
In order to prevent the undesired release of the hook, most snap hooks include a locking mechanism that that allows the user to control when the gate can be easily opened, and thus allow the attachment or release of the hook. The operation of the locking mechanism and the manner of opening of the gate are important factors in the selection and design of a safety snap hook. For example, a snap hook that is designed to attach to rigid anchoring points may simply include a locking gate that is released by finger actuated locking mechanism. The opening of the gate to engage the anchor point is then achieved by simply sliding the mouth of the hook over the anchor point, and the rigidity of the anchor point will urge the gate to open and the engagement of the hook with the anchor point. The user then simply releases the locking mechanism to ensure that the gate is locked in the closed position, preventing undesired release of the hook.
In other applications, the user must attach the safety hook to a horizontal lifeline, a D-ring, or other support point that may move away from the user as the gate is pressed against the support point. For these applications it is particularly useful to employ safety hooks where the user must be able to release the locking mechanism and open the gate with a single hand. These types of hooks typically include a finger operated locking mechanism and a gate with a thumb-operated lever that allows the user to open the gate. Examples of these devices include U.S. Pat. No. 4,434,536 to Schmidt et al., and U.S. Pat. No. 4,977,647 to Casebolt.
An important safety concern for safety hooks is that both the locking mechanism and the gate may both be inadvertently forced during a fall, causing the gate to open. This simultaneous forcing of both components can occur as a result of twisting or turning of the hook against a D-ring, for example. Thus, it is important to ensure that both the gate and the locking mechanism cannot be easily simultaneously exposed to a force urging both components to the open position. For example, if a portion of a D-ring or section of a lanyard is pressed against the lateral extension and the tongue of the Schmidt et al. invention, it is conceivable that both elements could be moved to the open position.
Another important design concern for safety hooks, is the design of a hook that uses few number of components, while maintaining the double action or double locking features desired in safety hooks. For example, it would be advantageous to provide the double locking features of the Casebolt design, without incorporating a separate spring for lock member or locking element, and the latch member or gate.
Therefore, a review of known devices reveals that there remains a need for a simple safety snap hook that is light and can accommodate single handed activation.
It has been discovered that the problems left unanswered by known art can be solved by providing a safety hook that includes:
a body having a hook portion that includes a mouth that terminates in a nose, the hook portion further having a shank portion;
a gate that is pivotally mounted from a gate pivot point on the shank portion and includes a closure portion that includes a heel portion and a toe portion, the toe portion cooperates with the nose of the hook to close off the mouth of the hook;
a locking element that is pivotally supported from a lock pivot that is positioned on the shank at a location between the gate pivot and the hook portion, the locking element having a trigger portion;
a peninsular portion extending between the locking element and the heel portion of the gate; and
a spring, the spring being mounted between and against the gate and the locking element, the spring urging the toe portion of the closure portion against the nose of the hook while urging the locking element against the peninsular portion, so that to release the gate the user simply rotates the locking element away from the peninsular portion and then rotates the closure portion in, towards the mouth of the hook.
According to an example of the invention, the locking element extends below the heel of the closure, on a first side of the peninsular portion, while the trigger portion is biased by the spring against an opposite side of the peninsular portion. With this configuration, simultaneous pressure on the closure and the trigger portion will not result in the release of the gate. Similarly, sequential pressure by first pressing and releasing the trigger and then pressing against the gate will not result in the opening of the gate. Thus it will be understood that the disclosed safety snap hook provides a simple mechanism that can be operated with a single hand.
It will be understood that the disclose safety snap hook achieves the benefits of known safety hooks, while eliminating parts.
It should also be understood that while the above and other advantages and results of the present invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings, showing the contemplated novel construction, combinations and elements as herein described, and more particularly defined by the appended claims, it should be clearly understood that changes in the precise embodiments of the herein disclosed invention are meant to be included within the scope of the claims, except insofar as they may be precluded by the prior art.
The accompanying drawings illustrate preferred embodiments of the present invention according to the best mode presently devised for making and using the instant invention, and in which:
FIG. 1 is a side view of an example of the invention.
FIG. 1A is an end view looking towards the mouth and trigger of the view shown in FIG. 1.
FIG. 2 is a side view of an example of the invention, the components of the example being shown as transparent in order to illustrate the arrangement of the components of the example.
FIG. 2A is an end view looking towards the mouth and trigger of the view shown in FIG. 1.
FIG. 3 illustrates the operation of the trigger and the gate of an example of the invention.
FIG. 4 includes the example shown in FIG. 3, with the components of the example being shown as transparent in order to illustrate the arrangement and cooperation of the components of the example.
FIG. 5 illustrates a pivotable connector attached to the shank of an example of the disclosed invention.
FIG. 6 illustrates a D-ring of the type often found on safety harnesses.
FIG. 7 illustrates the sizing of the hook portion of the disclosed invention in order to prevent false locking on a harness.
FIG. 8 illustrates the fit or cooperation of the safety snap hook and a D-ring.